HPCC-10159 Document SMART option for JOIN

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
HPCC-10159 edits based upon feedback

Signed-off-by: JamesDeFabia <James.Defabia@LexisNexis.com>
Update BltInFunc-JOIN.xml

HPCC-10159 Edits from code review
Update BltInFunc-JOIN.xml

HPCC-10159 Edits based upon review
Merge branch '10159DocsAddSmartOtionToJoin'

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>